In recent years, compact single focus lenses having a wide angle of view have been proposed (e.g. see Patent Document 1). Most zoom lenses used for compact digital cameras lately use retractable type lens barrels—well-known lens barrels where the lens barrel is retracted into the camera when the camera is not used. Further, just like a zoom lens, a wide angle single focus lens having a wide angle of view, which can retract the lens barrel into the camera when the camera is not used, and of which focal length does not change with respect to an object point at infinity, has also been proposed (e.g. see Patent Document 2).